Shelf life of 1% Pottasium Dichromate?

[M Carter]

Anyone know? I was having Bromoil issues and thought it was my 5 year old bottle, got some new and it's the same (real issue was unsuitable paper). But curious, in a sealed bottle out of the light, is it one of those "pretty much forever" chemicals?

 

[Vaughn]

Indefinite storage -- yes...one of those forever chemicals...not even light sensitive, as far as I know. However if contaminated with organic material (gelatin, some sizing, gum arabic, etc) it will go bad.

 

[mohmad khatab]

I recommend a very immersed developer
But it has a completely different flavor
Agfa14

 

[M Carter]

I recommend a very immersed developer
But it has a completely different flavor
Agfa14

Ummm... for tanning bromoil matrices?

 

[BrianShaw]

Indefinite storage -- yes...one of those forever chemicals...not even light sensitive, as far as I know. However if contaminated with organic material (gelatin, some sizing, gum arabic, etc) it will go bad.

I wish I knew that a few weeks ago. I dumped a bottle just because it was dated 1982.

 

[mohmad khatab]

Ummm... for tanning bromoil matrices?

Development of black and white film

 

[Vaughn]

I wish I knew that a few weeks ago. I dumped a bottle just because it was dated 1982.

I hope you were able to dump it properly. Nasty stuff -- but the hazard can be greatly diminished by treating it with Vit. C (Ascorbic acid).

 

[eli griggs]

I hope you were able to dump it properly. Nasty stuff -- but the hazard can be greatly diminished by treating it with Vit. C (Ascorbic acid).

By what ratio or measure?

 

[Vaughn]

Sprinkle it in until it changes color. The Ascorbic acid is pretty cheap.

 

[eli griggs]

Cheers!

 

[M Carter]

Development of black and white film

if you read my post, I'm discussing using it for tanning bromoils - A B&W film developer isn't going to work for that application.

 

[M Carter]

I hope you were able to dump it properly. Nasty stuff -- but the hazard can be greatly diminished by treating it with Vit. C (Ascorbic acid).

I've read that used fixer will work; will any acid do the same thing? I don't have ascorbic, but I have plenty of acid stop. I don't dump the straight stuff, but I do dump the bromoil bleach/tan, which has a few ML of 1% in the solution, depending on tray size.

 

[Andrew O'Neill]

I hope you were able to dump it properly. Nasty stuff -- but the hazard can be greatly diminished by treating it with Vit. C (Ascorbic acid).

That's great information. Thank you, Vaughn!

 

[Vaughn]

I've read that used fixer will work; will any acid do the same thing? I don't have ascorbic, but I have plenty of acid stop. I don't dump the straight stuff, but I do dump the bromoil bleach/tan, which has a few ML of 1% in the solution, depending on tray size.

In carbon printing we'll get some dichromate build up in the transfer bath, and cleaning things up. I just sprinkle it in the tray, stir it up a little and wait for the color change.

Ascorbic acid is cheap and easily bought online or in health food stores. On-line I have seen 5 pounds for $6/lb.

Other chemicals might work -- but this is cheap.

 

[Anon Ymous]

I've never heard that bichromate can be treated with ascorbic acid to convert it to something not carcinogenic. I'm sure sodium sulfite will convert hexavalent chromium to trivalent and this is something most of us have at hand.

 

[Steve Goldstein]

Ascorbic acid converts it from hexavalent to trivalent. That doesn't change the fact that it's a heavy metal, though.

 

[BJ68]

will any acid do the same thing?.

No....you need either fixer-Solution or ascorbic acid....see my posting https://www.photrio.com/forum/threads/dichromate-waste-treatment.135482/#post-1769722
New Link to the paper: https://www.researchgate.net/public...hromium_by_ascorbic_acid_in_aqueous_solutions because the link in the original post does not work anymore...

For example "citric acid" does not work: https://www.photrio.com/forum/threa...er-containing-dichromate.162887/#post-2121668

bj68